Ranunculus Planting GuideRanunculus Planting Guide

Arrival of Bulbs

Our Ranunculus bulbs are stored and shipped dry in a vegetative stage. If bulbs are not planted immediately, store them in a cool and well-ventilated area.

Keep the bulbs dry.
Do not expose to humidity.

Pre-Plant Soaking & Pre-Sprouting

Soak bulbs for 10–12 hours prior to planting in water at a maximum temperature of 12°C. It is recommended, although not essential, to keep the water moving, using slow running water or regularly changing the water, to maintain oxygen levels. A simple water tank or small container would be adequate.
When sufficiently soaked your bulbs should expand by 3 to 4 times their original size.
Once soaked, the Ranunculus bulbs then need to be stored in vermiculite. If using individual pots or seed cells to germinate, plant Ranunculus with its ‘fingers’ down to a depth of 1.5cm. They should remain moist but not be soaking wet. Store the bulbs for no less than 2 weeks at < + 10 °C.

Planting - Soil

Ranunculus can be grown in greenhouses, tunnels, under shade or outside. This mainly depends on the climate and season.
Plant bulbs in raised beds in a well-drained soil. For pot, container or raised platform cultivation, use a free draining sterilised medium, low in EC with a pH of 6-6.5.
Cover bulbs with 2–3 cm of soil.
Light intensity and good air flow is very important. Additional shade is recommended during the first 4 weeks after planting to keep the soil cool until the foliage creates its own canopy.
Optimum results can be achieved if the night temperatures are cool at 5–10°C and day temperatures do not exceed 15–18°C initially.
A light frost or warmer days does not hurt the plants as long as the root system remains at around +8°C. Provide additional ventilation if needed to control temperature and humidity.
We advise a planting density of:

Size 3/4: 20-24 bulbs/m2
Size 4/5: 16-20 bulbs/m2
Size 5/7: 14-18 bulbs/m2

Additional tips

For optimum results and even light distribution, support wire is recommended. Tall, straight stems are obtained when wire is used.
When harvesting, cut flowers early in the morning (coolest part of the day) with a sterilized knife.
Note – when temperatures rise to 24°C+, productivity will go down.

Grower FAQs

Extreme wet conditions and low light levels can make your plants more vulnerable for infection. The best way to keep Botrytis at bay is good air ventilation. Open tunnels as much as you can and introduce fans to keep the air moving. Drip irrigation as opposed to overhead is also recommended. Repeated applications of fungicide sprays will also help if possible to use.

Overwatering can cause root-rot and damage to foliage as oxygen flow to the roots is reduced. Ensure plant roots have good airflow and soil is free-draining to reduce the risk of overwatering. Typical signs of overwatering include severe lower leaf yellowing and leaf loss.

Ranunculus can be affected by low calcium levels in the soil, causing droopy stems. Ensure that soil has a balanced supply of nutrients, including calcium. Incorporate organic matter or fertiliser (e.g. gypsum) into the soil as it can improve soil structure and nutrient availability.